US researchers are trumpeting a new drug as a “game changer” in the management of obesity – and for once, a large, gold-standard clinical trial backs up the hype.

A single weekly injection of the drug semaglutide, for 68 weeks, saw an average loss of 15 percent body weight in trial participants.

Those given a placebo, in tandem with a diet and exercise program, lost 2.4 per cent of their body weight.

More than a third of the participants who took the drug lost more than 20 percent of their weight.

This prompted the ordinarily sober New York Times, citing the researchers, to write: “For the first time, a drug has been shown so effective against obesity that patients may dodge many of its worst consequences, including diabetes.”

As experts told the Times, these results far exceed the amount of weight loss observed in clinical trials of other obesity medications.

The drug is a “game-changer,” said Dr. Robert F. Kushner, an obesity researcher at Northwestern University Feinberg School of Medicine, who led the study. “This is the start of a new era of effective treatments for obesity.”

No long wait required. The drug is already in Australia

Semaglutide isn’t brand new. It was discovered in 2012 by researchers at Novo Nordisk, a Danish healthcare company with a focus on chronic disease. Novo Nordisk funded the latest trial.

The drug was approved in 2017 by the USFDA as an injectable type II diabetes treatment.

The New Daily has found that, for the last four months, the drug has been prescribed off-label “for diabetic care and as a weight loss agent” by Western Australian bariatric surgeon, Dr Leon Cohen.

Dr Leon Cohen, surgeon and director of Mercy Bariatrics in WA has been prescribing the new weight-loss drug for about four months.

Dr Cohen said his patients had been getting similar results to that achieved in the clinical trial – but at a much lower dose.

“The drug usually comes with a starting dose of 0.25mg and then you gradually build it up to 1mg,” he said.

In the new trial, participants – who had a BMI of 30 or more, and thus technically obese – were given 2.4mg as an anti-obesity medicine.

The drug mimics a naturally occurring hormone

Dr Cohen said the drug mimics GLP-1, a gut hormone that’s released in response to undigested food hitting the distal small bowel.

“It’s an interesting and exciting mechanism, because essentially what the body needs is a mechanism which can sense you’ve just had a large meal and there’s still a lot of undigested food that hasn’t been absorbed,” he said.

“Now it’s reaching the small bowel, so its time to tell the body to stop eating.”

Dr Cohen, on his clinic website, reports: “We are starting to see encouraging results from administration of a new weight loss drug Ozempic (Semaglutide) as an adjunct in the management of weight regain or in low BMI patients trying to avoid surgery.”

He said that for people with a relatively low BMI seeking an alternative to bariatric surgery – and by that he means people who have started to creep into obese territory – the drug has resulted in “quite respectable weight loss.”

Morbidly obese people still need surgery

He said: “It doesn’t matter what treatment you give to someone with a low BMI, they get a good result. They only need to lose 10 kilos and you get a very respectable percentage of your weight loss.

“We know that anyone with diabetes who loses 10 per cent of their weight, it’s going to help a lot with their diabetes control.”

But most of his patients have a BMI over 40 and surgery remains their only viable option. “If they lose 20 per cent of their weight it’s pretty good, but it doesn’t compare to surgery which achieves 35 to 40 per cent loss.”

Dr Cohen allowed that very few people who needed surgery could either afford it or were willing to take it up.

It appears that for type II diabetics, or people edging into obesity, this new drug may be the game changer as touted by its makers. Side effects tend to be, in the main, mild gastrointestinal complaints. Long term effects at the higher dose are unknown.

And while a weekly injection might cost up to US$1000 ($A1292) in the USA, Dr Cohen’s patients are charged $160 a month. He said for people with poorly controlled diabetes, with an authority script, the cost could be much lower.

But once you’re on semaglutide, it’s probably for life. Trial participants rejoiced at their weight loss. But once they stopped taking the drug, the weight came back.